The inner layer of the cornea is a single layer of neural crest-derived endothelial cells (CECs), which form a barrier between the cornea and the aqueous humor and transport water from the corneal stroma. CEC loss can result from eye injuries, complications from cataract surgery (pseudophakic bullous keratopathy (PBK) or aphakic bullous keratopathy (ABK)), and in an inherited condition known as Fuchs dystrophy.
These cells do not divide during adult life. Rather, existing CECs simply spread to compensate for loss or damage. When this spreading is inadequate, vision-impairing corneal opacity results.
Traditional treatment for CEC loss or damage is penetrating keratoplasty (PK), in which a full thickness cadaveric cornea is transplanted onto a recipient eye. However, a procedure known as DSEK (Descemet's Stripping and Endothelial Keratectomy) may be an option in some cases in which the corneal stroma is not scarred. In this procedure. CECs and their underlying basement membrane (Descemet's membrane) are physically removed from the recipient, and only the inner portion of a donor cadaveric cornea, including intact CECs, is transferred to the recipient eye.
More recently, the DMEK procedure (Descemet's Membrane Endothelial Keratoplasty) has been developed, in which the donor cadaveric tissue consists only of Descemet's membrane and CEC layers Cultured CECs on synthetic films is also under study. Tissue engineered scaffold coated with corneal endothelium, is an optional way to address the shortage of cornea donors. Researchers have recently reported on the fabrication of collagen sheets used as the corneal scaffold (Koizumi et al., 2007, Invest Ophthalmol Vis Sci 10 (10): 4519-26). One of drawbacks of collagen sheet is that the scaffolds have a low transparency. Chemical cross-linking of collagen solution may be a better method to fabricate scaffolds with high transparency and proper mechanical strength (Liu et al., 2008, Biomaterials 29 (9): 1147-58). However, the solubility of natural collagen is limited, resulting in a high viscous solution at a high concentration.
However, more options are needed to provide suitable restoration of the corneal endothelial cell layer, as well as the creation for tissue engineered construct for use in corneal endothelium transplantation. The present invention addresses this unmet need in the art.